News - Green tea may protect DNA from damage
Combined results from a human supplementation trial and a laboratory study suggest that drinking green tea every day may protect against damage at a genetic level. The study, published in the British Journal of Nutrition, adds to an ever-growing body of science supporting the potential benefits of green tea and the antioxidant compounds it contains.
To carry out the study, the researchers recruited 18 healthy volunteers and randomly assigned them to receive either two cups of green tea or water every day for four weeks. After a six-week wash-out period, the two groups were swapped over and the tests were repeated. Blood and urine samples were collected before and after each intervention so the scientists could measure the level of DNA damage.
The analysis showed that four weeks of drinking green tea reduced the level of DNA damage by 20%.
In the laboratory study, the scientists treated human blood cells with green tea and then exposed the cells to the oxidising agent hydrogen peroxide. They found that the DNA in cells that had been pre-treated with green tea was much more resistant to the oxidative stress than that of the untreated blood cells.
Commenting on their results, the scientists said: “The results indicate that green tea has significant genoprotective effects and provide evidence for green tea as a ‘functional food’”.
Han KC, Wong WC, Benzie IF. Genoprotective effects of green tea (Camellia sinensis) in human subjects: results of a controlled supplementation trial. Br J Nutr. (2010) [Epub ahead of print]